CN102257036A - Photocurable resin composition for ultraviolet led irradiation - Google Patents

Abstract

Disclosed is a photocurable resin composition for a UV-LED light source that cures quickly and exhibits excellent surface hardening properties in particular. The photocurable resin composition contains (a) a polybutadiene (meth)acrylate, (b) a polythiol compound, and (c) a photo-radical initiator, and is cured by irradiation with an ultraviolet LED. Thus, production efficiency can be improved significantly in the production of liquid crystal display devices, electric/electronic components, and the like.

Description

Photocurable resin composition with ultraviolet light-LED radiation

technical field

The present invention relates to a photocurable resin composition which is cured by using UV-LED radiation.

Background technique

In recent years, light emitting diodes (LED for short) have been used as a substitute for conventional light sources in various fields because they save power consumption. Ultraviolet light-LEDs (hereinafter referred to as UV-LEDs) have been proposed as light sources for curing photocurable resins (Patent Document 1: JP-A-2008-163,183). UV-LEDs generally have a unimodal wavelength distribution. It is expected to use UV-LEDs with peaks at eg 360nm-370nm to reduce UV light damage mainly due to short wavelengths and also to increase production efficiency.

However, UV-LEDs lack the short wavelength light (eg, range no greater than 300 nm, even no greater than 350 nm) needed to reduce oxygen inhibition and achieve acceptable surface curing. Therefore, curing by UV-LED as a light source has the problem of curing defects on the resin surface caused by oxygen inhibition.

Literature list

Patent Document 1: JP-A-2008-163,183

Patent Document 2: JP-A-H1-22,927 (JP-B-H6-60,238)

Contents of the invention

The present inventors devoted themselves to research to realize a photocurable resin composition suitable for UV-LED light sources. However, the surface curing properties when using conventional light sources have little correlation with those when using UV-LEDs.

For example, a photocurable resin composition comprising a polyolefin compound or a (meth)acrylate compound and a polythiol compound (for example, see the background art section of Patent Document 2: JP-A-H1-22,927) is known, However, it is extremely difficult to find a suitable composition excellent in surface curing properties when using a high-pressure mercury lamp, because the surface curing properties decrease when a polythiol compound is added, or because the surface curing properties decrease when using UV-LEDs.

Under such circumstances, the present inventors have found that a combination of a specific (meth)acrylate component and a polythiol compound will provide a photocurable resin composition having excellent surface curing properties, and thus the present inventors have achieved the invention.

Thus, the present invention relates to the following aspects.

1. A resin composition curable by UV-LED radiation, comprising:

(a) polybutadiene (meth)acrylate;

(b) polythiol compounds; and

(c) Photoradical initiator.

2. The composition according to the above item 1, wherein based on 100 parts by weight of polybutadiene (meth)acrylate (a), the composition contains 0.5-100 parts by weight of polythiol compound ( b) and 0.1-20 parts by weight of photoradical initiator (c).

3. The composition according to the above item 1 or 2, wherein the polythiol compound includes a polythiol compound containing 3 or more SH groups in one molecule.

4. The composition according to any one of the above items 1-3, wherein, based on 100 parts by weight of polybutadiene (meth)acrylate (a), the composition further comprises 10-200 (meth)acrylic monomer and/or (meth)acrylic oligomer in parts by weight.

The present invention can provide a photocurable resin composition for a UV-LED light source, which cures quickly, and particularly has excellent surface curing properties. As a result, production efficiency can be significantly improved in the production of liquid crystal displays and electronic and electrical components.

Furthermore, since the composition of the present invention is excellent in moisture resistance and adhesiveness, the composition is suitable for use as a moisture-proof coating agent for electrode materials such as ITO.

Detailed ways

The (a) polybutadiene (meth)acrylate used in the present invention has a polybutadiene structure in its molecule, and has a (meth)acryloyl group at its terminal. It is preferably a liquid and has a viscosity at 25°C in the range of 1000-1000000 cps, more preferably a viscosity in the range of 2000-700000 cps. The polybutadiene structure may be a 1,2-polybutadiene structure or a 1,4-polybutadiene structure, and they may also be mixedly contained in the molecule.

Specific examples thereof include liquid polybutadiene (meth)acrylates obtained from the urethane addition reaction of 2-hydroxyethyl (meth)acrylate with hydroxyl groups, wherein the hydroxyl groups are liquid polybutadiene through 2, Contained in 4-toluene diisocyanate; liquid polybutadiene (meth)acrylate obtained from the esterification of 2-hydroxy (meth)acrylate with maleinated polybutadiene by adding Maleic anhydride is added into the reaction; liquid polybutadiene (meth)acrylate obtained from the epoxy esterification reaction of glycidyl (meth)acrylate with carboxyl groups contained in polybutadiene; obtained from (meth) ) liquid polybutadiene (meth)acrylate obtained from the esterification reaction of acrylic acid with epoxidized polybutadiene obtained by applying an epoxidizing agent to liquid polybutadiene; obtained from Liquid polybutadiene (meth)acrylate obtained from the dehydrochlorination reaction of (meth)acryloyl chloride and hydroxyl-containing liquid polybutadiene; and obtained from the reaction of liquid 1 with urethane-(meth)acrylate, 2-polybutadiene diol modified liquid hydrogenated 1,2-polybutadiene (meth)acrylate, etc.

These are available from Nippon Soda Co., Ltd. under the product names TEA-1000 and TE-2000, from Osaka Organic Chemical Industry Ltd. under the product names BAC-45, BAC-15, SPBDA-30, SPBDA-50, and under the product names CN301, CN303, CN307 were purchased from Sartomer Company Inc.

The (b) polythiols used in the present invention are those polythiols containing 2 or more SH groups in their molecules. Specifically, aliphatic polythiol compounds include dithiol compounds such as 1,2-ethanedithiol, 1,2-propanedithiol, 1,3-propanedithiol, 1,4-butane Dithiol, 1,6-Hexanedithiol, 1,7-Heptanedithiol, 1,8-Octanedithiol, 1,9-Nonanedithiol, 1,10-Decane Dithiol, 1,12-dodecanedithiol, 2,2-dimethyl-1,3-propanedithiol, 3-methyl-1,5-pentanedithiol, 2-methyl Base-1,8-octanedithiol, 1,4-cyclohexanedithiol, 1,4-bis(mercaptomethyl)cyclohexane, 1,1-cyclohexanedithiol, 1, 2-cyclohexanedithiol, bicyclo[2,2,1]hept-exo-cis-2,3-dithiol, 1,1-bis(mercaptomethyl)cyclohexane, bis(2-mercapto Ethyl) ether, ethylene glycol bis(2-mercaptoacetate) and ethylene glycol bis(3-mercaptopropionate); trithiol compounds such as 1,1,1-tris(mercaptomethyl)ethane Alkanes, 2-ethyl-2-mercaptomethyl-1,3-propanedithiol, 1,2,3-propanetrithiol, triformylpropane tris(2-mercaptoacetate), triformylpropane tris (3-mercaptopropionate) and tris((mercaptopropionyloxy)-ethyl)isocyanurate; and thiol compounds containing 4 or more SH groups, such as pentaerythritol tetrakis(2-mercapto acetate), pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), and dipentaerythritol hexa-3-mercaptopropionate.

In addition, aromatic polythiol compounds include 1,2-dimercaptobenzene, 1,3-dimercaptobenzene, 1,4-dimercaptobenzene, 1,2-bis(mercaptomethyl)benzene, 1,3-bismercaptobenzene, (Mercaptomethyl)benzene, 1,4-bis(mercaptomethyl)benzene, 1,2-bis(2-mercaptoethyl)benzene, 1,3-bis(2-mercaptoethyl)benzene, 1,4 -bis(2-mercaptoethyl)benzene, 1,2-bis(2-mercaptoethyleneoxy)benzene, 1,3-bis(2-mercaptoethyleneoxy)benzene, 1,4-bis(2-mercapto Vinyloxy)benzene, 1,2,3-trimercaptobenzene, 1,2,4-trimercaptobenzene, 1,3,5-trimercaptobenzene, 1,2,3-tris(mercaptomethyl)benzene, 1,2,4-tri(mercaptomethyl)benzene, 1,3,5-tri(mercaptomethyl)benzene, 1,2,3-tri(2-mercaptoethyl)benzene, 1,2,4- Tris(2-mercaptoethyl)benzene, 1,3,5-tris(2-mercaptoethyl)benzene, 1,2,3-tris(2-mercaptoethyleneoxy)benzene, 1,2,4-tris (2-Mercaptoethyleneoxy)benzene, 1,3,5-tris(2-mercaptoethyleneoxy)benzene, 1,2,3,4-tetramercaptobenzene, 1,2,3,5-tetramercaptobenzene , 1,2,4,5-tetramercaptobenzene, 1,2,3,4-tetra(mercaptomethyl)benzene, 1,2,3,5-tetra(mercaptomethyl)benzene, 1,2,4 , 5-tetra(mercaptomethyl)benzene, 1,2,3,4-tetrakis(2-mercaptoethyl)benzene, 1,2,3,5-tetrakis(2-mercaptoethyl)benzene, 1,2 , 4,5-tetrakis(2-mercaptoethyl)benzene, 1,2,3,4-tetrakis(2-mercaptoethyleneoxy)benzene, 1,2,3,5-tetrakis(2-mercaptoethyleneoxy) ) benzene, 1,2,4,5-tetra(2-mercaptoethyleneoxy)benzene, 2,2'-dimercaptobiphenyl, 4,4'-thiobis-benzenethiol, 4,4'- Dimercaptobiphenyl, 4,4'-dimercaptodiphenyl, 2,5-toluenedithiol, 3,4-toluenedithiol, 1,4-naphthalenedithiol, 1,5-naphthalenedithiol , 2,6-naphthalenedithiol, 2,7-naphthalenedithiol, 2,4-dimethylbenzene-1,3-dithiol, 4,5-dimethylbenzene-1,3-di Mercaptan, 9,10-anthracene dimethanethiol, 1,3-bis(2-mercaptoethylthio)benzene, 1,4-bis(2-mercaptoethylthio)benzene, 1,2-bis (2-Mercaptoethylthiomethyl)benzene, 1,3-bis(2-mercaptoethylthiomethyl)benzene, 1,4-bis(2-mercaptoethylthiomethyl)benzene, 1 , 2,3-tris(2-mercaptoethylthio)benzene, 1,2,4-tris(2-mercaptoethylthio)benzene, 1,3,5-tris(2-mercaptoethylthio) ) benzene, 1,2,3,4-tetrakis(2-mercaptoethylthio)benzene, 1,2,3,5-tetrakis(2-mercaptoethylthio)benzene, and 1,2,4, 5-Tetrakis(2-mercaptoethylthio)benzene, etc.

In addition, polythiol compounds containing thioether bonds in the molecule include bis(2-mercaptoethyl)sulfide, bis(2-mercaptoethylthio)methane, 1,2-bis(2-mercaptoethylthio) ) ethane, 1,3-bis(2-mercaptoethylthio)propane, 1,2,3-tris(2-mercaptoethylthio)propane, tetrakis(2-mercaptoethylthiomethyl) Methane, 1,2-bis(2-mercaptoethylthio)propanethiol, 2,5-dimercapto-1,4-dithiane, bis(2-mercaptoethyl)sulfide, 3,4- Thiophenedithiol, 1,2-bis(2-mercaptoethyl)thio-3-mercaptopropane, bis-(2-mercaptoethylthio-3-mercaptopropane)sulfide, and the like.

Particularly preferred polythiol compounds are trivalent (containing 3 or more SH groups) or higher (usually about 8 or less) aliphatic polythiols, and especially preferred are trimethylol Propane tris(2-mercaptoacetate), triformylpropane tris(3-mercaptopropionate), tris((mercaptopropionyloxy)-ethyl)isocyanurate, pentaerythritol tetrakis(2-mercaptoethane) ester), pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), dipentaerythritol hexa-3-mercaptopropionate, etc.

In the composition of the present invention, it is preferred that at least a part of the polythiol compound contained is a trivalent or higher (usually about 8-valent or lower) polythiol compound, and the polythiol compound contained The whole is a trivalent or higher polythiol compound.

In the composition, based on 100 parts by weight of polybutadiene (meth)acrylate, the content ratio of (b) polythiol compound is usually 0.5-100 parts by weight, preferably 2-50 parts by weight, and more preferably 5-30 parts by weight.

(c) The photoradical initiator may be a compound that generates radicals by irradiating ultraviolet light using an emission wavelength of the UV-LED.

The photoradical initiators may include acetophenone-based initiators such as diethoxyacetophenone and benzyl dimethyl ketal, benzoin ether-based initiators such as benzoin and benzoin Azoin ethyl ether, benzophenone-based initiators such as benzophenone and methyl phthaloylbenzoate, alpha-diketone-based initiators such as diacetyl, and benzyl and acetyl Naphthophenones, and thio compounds such as methylthioxanthone.

More specific examples include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminobenzene Ethanone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy -2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methyl Thio)phenyl]-2-morpholinyl-propan-1-one, 4-(2-hydroxyethoxy)phenyl-2(hydroxy-2propyl)one, benzophenone, p-phenyl Benzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2- Aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, Benzyl dimethyl ketal, acetophenone dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoate, and oligo(2-hydroxy-2-methyl-1 -[4-(1-propenyl)phenyl]acetone) and the like.

A particularly preferred initiator has strong absorption in a wavelength range not shorter than 350 nm, and it includes Irgacure 369 (2-benzyl-2-(dimethylamino)-1-[4-(4- Morpholinyl)phenyl]-1-butanone), Irgacure 907 (2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholino)-1-propanone ), Irgacure 819 (phenylbis(2,4,6-trimethylbenzoyl)-phosphine oxide), and DarocureTPO (diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide things) etc.

In addition to the photoinitiators mentioned, known sensitizers can also be used.

The content of the (c) photoradical initiator is generally 0.1-20 parts by weight, and preferably 1-10 parts by weight, based on 100 parts by weight of polybutadiene (meth)acrylate.

In the composition of the present invention, in addition to the aforementioned polybutadiene (meth)acrylate, (meth)acrylic monomers and/or (meth)acrylic oligomers can optionally be used as Components used in combination with the photocurable resin.

Monofunctional (meth)acrylic monomers include, for example, butylene glycol mono(meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentanyl (meth)acrylate Enyl ester, dicyclopentenyloxyethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, (meth) 2-Hydroxyethyl acrylate, 2-Hydroxypropyl (meth)acrylate, 2-Hydroxyethyl (meth)acrylate modified by caprolactone, Isobornyl (meth)acrylate, Lauryl (meth)acrylate ester, acryloylmorpholine, N-vinylcaprolactam, nonylphenoxy polyethylene glycol (meth)acrylate, nonylphenoxy polypropylene glycol (meth)acrylate, phenoxy (meth)acrylate ethyl ethyl ester, phenoxyhydroxypropyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, and Tetrahydrofurfuryl (meth)acrylate, etc.

Multifunctional (meth)acrylic monomers include, for example, 1,4-butylene glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, ethylene glycol di(meth)acrylate, hexa Dipentaerythritol (meth)acrylate, dipentaerythritol hexa(meth)acrylate modified by caprolactone, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate ester, pentaerythritol tri(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, trimethylolpropane trimethylolpropane (Meth)acrylates, Tris(acryloyloxyethyl)isocyanurate, Caprolactone-modified Tris(acryloyloxyethyl)isocyanurate, Tris(methacryloyloxy ethyl) isocyanurate, and tricyclodecane dimethanol di(meth)acrylate, etc.

These monofunctional (meth)acrylic monomers and polyfunctional (meth)acrylic monomers may be used alone or in combination of two or more monomers, or the monofunctional and polyfunctional monofunctional body combination.

Furthermore, the (meth)acrylic oligomers are those having at least one (meth)acryloyl group, and they include, for example, epoxy acrylate, urethane acrylate, polyester acrylate, polyol acrylate , polyether acrylate, silicone resin acrylate, and melamine acrylate, etc.

As a component used in combination, a monofunctional (meth)acrylate compound can be preferably used for viscosity adjustment and/or physical property adjustment. In certain applications, cycloaliphatic (meth)acrylate compounds such as isobornyl acrylate are preferred.

Based on 100 parts by weight of polybutadiene (meth)acrylate, the content ratio of the acrylic monomer and/or acrylic oligomer is preferably 0-300 parts by weight, more preferably 10-200 parts by weight.

The composition of the present invention may also contain additives and resin components etc. to improve or improve properties such as flowability, coating properties, anti-corrosion properties, curing properties and physical properties after curing.

Components that may be included as required include, for example, organic or inorganic fillers, thixotropic agents, silane coupling agents, diluents, modifiers, colorants (such as pigments and dyes), surfactants, preservatives-stabilizers, Plasticizers, lubricants, defoamers, and leveling agents, etc.; but not limited to these. In particular, the composition preferably contains additives selected from fillers, thixotropic agents, and silane coupling agents.

The fillers include, but are not particularly limited to, for example inorganic fillers such as silica, diatomaceous earth, alumina, zinc oxide, iron oxide, magnesium oxide, tin oxide, titanium oxide, magnesium hydroxide, aluminum hydroxide, magnesium carbonate , barium sulfate, gypsum, calcium silicate, talc, glass beads, sericite activated clay, bentonite, aluminum nitride, and silicon nitride.

The thixotropic agent includes, but is not particularly limited to, for example, talc, fine-grained silica, ultra-fine surface-treated calcium carbonate, fine-grained alumina, flaky alumina; layered compounds such as montmorillonite; and acicular Compounds, such as aluminum borate whiskers, etc. Among them, talc, fine particle silica, composite fine particle alumina, and the like are preferable.

The silane coupling agent includes but not particularly limited to γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-shrink Glyceryloxypropyltrimethoxysilane, SH6062, SZ6030 (the above are purchased from Toray-Dow Corring Silicone Inc.), KBE903, KBM803 (the above are purchased from Shin-Etsu Silicone Inc.), etc.

The photocurable resin composition of the present invention can be obtained by mixing the above-mentioned components, for example, using a mixer such as a stirrer with stirring blades and a three-roll mill. The photocurable composition is liquid at an application temperature which is preferably ambient temperature (working environment temperature), and the mass to be formulated, in particular all resinous materials, need not be liquid.

The composition of the present invention obtained as above can be cured by light irradiation using a UV-LED. As for the applicable UV-LED, any UV-LED can be used as long as its emission wavelength range overlaps with the wavelength capable of activating the photoradical initiator. In applications where it is necessary to avoid UV damage to materials (such as for liquid crystal displays, etc.), UV-LEDs with peak wavelengths not shorter than 300nm, such as 350-380nm, preferably 360-370nm, are preferred.

By using the above UV-LEDs, the curing (internal curing and non-stick surface curing) of 300 μm thickness can be performed for a duration of not longer than 30 seconds, preferably not longer than 10 seconds, using radiation of 100 mW/cm ² , because the present invention The composition has excellent surface curing properties. As long as it can be cured, the lower limit of the UV-LED irradiation time can be very short; but due to the certainty of the irradiation, it is usually not shorter than about 0.5 second, for example not shorter than about 1 second.

Example

Compositions were obtained by mixing the materials shown in Table 1 well enough using a mixer. About 50 mg of the composition was coated on a glass slide and irradiated with light from a UV-LED or a high-pressure mercury lamp. For the UV-LED device, ANUJ5012 manufactured by Panasonic was used, and its radiation intensity was set at 100 mW/cm ² . In addition, Technoflux IH-153 was used for the high-pressure mercury lamp, and its radiation intensity was set at 100 mW/cm ² .

surface curing properties

After a certain duration of light radiation, talcum powder is spread on the surface of the composition, then gently brushed off, then the surface of the composition is observed, and the tack-free time (tack-freetime) (talc method) is determined. ). Insufficient surface curing was determined when talc remained on the surface of the composition, and complete surface curing was determined when no talc remained on the surface of the composition. The tack-free time is given when the surface is completely cured.

double bond conversion

For the samples before light irradiation and after 5 seconds of irradiation using a UV-LED light source, using FT-IR, the double bond conversion rate was determined from the decrease of the double bond absorption peak.

Table 1

^* 1) Polybutadiene acrylate manufactured by Nippon Soda Co., Ltd.

^* 2) Isobornyl acrylate manufactured by Osaka Organic Chemical Industry Ltd.

^* 3) Urethane acrylate manufactured by Sartomer Company Inc.

^* 4) Polythiol compound, trimethylolpropane tris(3-mercaptopropionate), manufactured by Yodo Kagaku Co., Ltd.

^* 5) Polythiol compound pentaerythritol tetrakis(3-mercaptobutyrate) manufactured by Showa Denko.

^* 6), ^* 7) Photoinitiators manufactured by Ciba Specialty Chemicals.

^* 8) Use Panasonic ANUJ 5012.

^* 9) Using Technoflux IH-153.

^* TFT: Tack-free time.

Comparing Examples 1 and 2 with Comparative Example 2, there is no difference in tack-free time for light irradiation using a high-pressure mercury lamp. However, for light irradiation using UV-LEDs, only Examples 1 and 2 containing the polythiol compound achieved rapid surface curing, while Comparative Example 1 containing no polythiol compound was poor in surface curing properties. In addition, comparing Example 1 with Comparative Example 3, even if the polythiol was added, other (meth)acrylate oligomers (non-polybutadiene (meth)acrylate) were not compatible with the polythiol Alcohol combinations are not as good in surface curing properties. In particular, comparing Comparative Example 2 with Comparative Example 3, the surface curing property is worse due to the addition of polythiol.

As evident from the above, various modifications are possible unless departing from the spirit of the invention. Accordingly, the embodiments described herein are exemplary and they do not limit the scope of the invention as described in the claims.

Industrial Applicability

The present invention can provide a photocurable resin composition for UV-LED, which is fast cured, and particularly has excellent surface curing properties. As a result, production efficiency can be significantly increased in the production of liquid crystal displays and electrical and electronic components.

Claims (4)

1. A photocurable resin composition by ultraviolet light-LED radiation, comprising: (a) polybutadiene (meth)acrylate; (b) polythiol compounds; and (c) Photoradical initiator. 2. The composition of claim 1, wherein, based on 100 parts by weight of polybutadiene (meth)acrylate (a), said composition comprises 0.5-100 parts by weight of polythiol compound (b) and 0.1 - 20 parts by weight of photoradical initiator (c). 3. The composition of claim 1, wherein the polythiol compound comprises a polythiol compound comprising 3 or more SH groups in one molecule. 4. The composition of any one of claims 1-3, wherein, based on 100 parts by weight of polybutadiene (meth)acrylate (a), said composition also comprises 10-200 parts by weight of (form base) acrylic monomers and/or (meth)acrylic oligomers.